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authorSteven Whitehouse <swhiteho@redhat.com>2009-09-28 07:35:17 -0400
committerSteven Whitehouse <swhiteho@redhat.com>2009-12-03 06:53:02 -0500
commit86e931a35e93d94e6e91b57cc76456e16d188ea9 (patch)
tree55078897d1c3dfa43fed6458a7721af17362b4a3 /fs/quota
parente285c100362762f7440643be637dd332460fdc75 (diff)
VFS: Export dquot_send_warning
Sending a message to userspace in a generic format to warn of events (e.g. quota exceeded) in the quota subsystem is a generically useful feature. This patch makes some minor changes to the send_message function from dquot.c renaming it quota_send_message, moving it to quota.c and exporting it for use by filesystems which do not use the dquot code. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/quota')
-rw-r--r--fs/quota/Kconfig2
-rw-r--r--fs/quota/dquot.c93
-rw-r--r--fs/quota/quota.c93
3 files changed, 103 insertions, 85 deletions
diff --git a/fs/quota/Kconfig b/fs/quota/Kconfig
index 8047e01ef46b..353e78a9ebee 100644
--- a/fs/quota/Kconfig
+++ b/fs/quota/Kconfig
@@ -17,7 +17,7 @@ config QUOTA
17 17
18config QUOTA_NETLINK_INTERFACE 18config QUOTA_NETLINK_INTERFACE
19 bool "Report quota messages through netlink interface" 19 bool "Report quota messages through netlink interface"
20 depends on QUOTA && NET 20 depends on QUOTACTL && NET
21 help 21 help
22 If you say Y here, quota warnings (about exceeding softlimit, reaching 22 If you say Y here, quota warnings (about exceeding softlimit, reaching
23 hardlimit, etc.) will be reported through netlink interface. If unsure, 23 hardlimit, etc.) will be reported through netlink interface. If unsure,
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 39b49c42a7ed..9b6ad908dcb2 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -77,10 +77,6 @@
77#include <linux/capability.h> 77#include <linux/capability.h>
78#include <linux/quotaops.h> 78#include <linux/quotaops.h>
79#include <linux/writeback.h> /* for inode_lock, oddly enough.. */ 79#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
80#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
81#include <net/netlink.h>
82#include <net/genetlink.h>
83#endif
84 80
85#include <asm/uaccess.h> 81#include <asm/uaccess.h>
86 82
@@ -1071,73 +1067,6 @@ static void print_warning(struct dquot *dquot, const int warntype)
1071} 1067}
1072#endif 1068#endif
1073 1069
1074#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1075
1076/* Netlink family structure for quota */
1077static struct genl_family quota_genl_family = {
1078 .id = GENL_ID_GENERATE,
1079 .hdrsize = 0,
1080 .name = "VFS_DQUOT",
1081 .version = 1,
1082 .maxattr = QUOTA_NL_A_MAX,
1083};
1084
1085/* Send warning to userspace about user which exceeded quota */
1086static void send_warning(const struct dquot *dquot, const char warntype)
1087{
1088 static atomic_t seq;
1089 struct sk_buff *skb;
1090 void *msg_head;
1091 int ret;
1092 int msg_size = 4 * nla_total_size(sizeof(u32)) +
1093 2 * nla_total_size(sizeof(u64));
1094
1095 /* We have to allocate using GFP_NOFS as we are called from a
1096 * filesystem performing write and thus further recursion into
1097 * the fs to free some data could cause deadlocks. */
1098 skb = genlmsg_new(msg_size, GFP_NOFS);
1099 if (!skb) {
1100 printk(KERN_ERR
1101 "VFS: Not enough memory to send quota warning.\n");
1102 return;
1103 }
1104 msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
1105 &quota_genl_family, 0, QUOTA_NL_C_WARNING);
1106 if (!msg_head) {
1107 printk(KERN_ERR
1108 "VFS: Cannot store netlink header in quota warning.\n");
1109 goto err_out;
1110 }
1111 ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
1112 if (ret)
1113 goto attr_err_out;
1114 ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
1115 if (ret)
1116 goto attr_err_out;
1117 ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
1118 if (ret)
1119 goto attr_err_out;
1120 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
1121 MAJOR(dquot->dq_sb->s_dev));
1122 if (ret)
1123 goto attr_err_out;
1124 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
1125 MINOR(dquot->dq_sb->s_dev));
1126 if (ret)
1127 goto attr_err_out;
1128 ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
1129 if (ret)
1130 goto attr_err_out;
1131 genlmsg_end(skb, msg_head);
1132
1133 genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
1134 return;
1135attr_err_out:
1136 printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
1137err_out:
1138 kfree_skb(skb);
1139}
1140#endif
1141/* 1070/*
1142 * Write warnings to the console and send warning messages over netlink. 1071 * Write warnings to the console and send warning messages over netlink.
1143 * 1072 *
@@ -1145,18 +1074,20 @@ err_out:
1145 */ 1074 */
1146static void flush_warnings(struct dquot *const *dquots, char *warntype) 1075static void flush_warnings(struct dquot *const *dquots, char *warntype)
1147{ 1076{
1077 struct dquot *dq;
1148 int i; 1078 int i;
1149 1079
1150 for (i = 0; i < MAXQUOTAS; i++) 1080 for (i = 0; i < MAXQUOTAS; i++) {
1151 if (dquots[i] && warntype[i] != QUOTA_NL_NOWARN && 1081 dq = dquots[i];
1152 !warning_issued(dquots[i], warntype[i])) { 1082 if (dq && warntype[i] != QUOTA_NL_NOWARN &&
1083 !warning_issued(dq, warntype[i])) {
1153#ifdef CONFIG_PRINT_QUOTA_WARNING 1084#ifdef CONFIG_PRINT_QUOTA_WARNING
1154 print_warning(dquots[i], warntype[i]); 1085 print_warning(dq, warntype[i]);
1155#endif
1156#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
1157 send_warning(dquots[i], warntype[i]);
1158#endif 1086#endif
1087 quota_send_warning(dq->dq_type, dq->dq_id,
1088 dq->dq_sb->s_dev, warntype[i]);
1159 } 1089 }
1090 }
1160} 1091}
1161 1092
1162static int ignore_hardlimit(struct dquot *dquot) 1093static int ignore_hardlimit(struct dquot *dquot)
@@ -2607,12 +2538,6 @@ static int __init dquot_init(void)
2607 2538
2608 register_shrinker(&dqcache_shrinker); 2539 register_shrinker(&dqcache_shrinker);
2609 2540
2610#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
2611 if (genl_register_family(&quota_genl_family) != 0)
2612 printk(KERN_ERR
2613 "VFS: Failed to create quota netlink interface.\n");
2614#endif
2615
2616 return 0; 2541 return 0;
2617} 2542}
2618module_init(dquot_init); 2543module_init(dquot_init);
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 95c5b42384b2..ee91e2756950 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -18,6 +18,8 @@
18#include <linux/capability.h> 18#include <linux/capability.h>
19#include <linux/quotaops.h> 19#include <linux/quotaops.h>
20#include <linux/types.h> 20#include <linux/types.h>
21#include <net/netlink.h>
22#include <net/genetlink.h>
21 23
22/* Check validity of generic quotactl commands */ 24/* Check validity of generic quotactl commands */
23static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, 25static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
@@ -525,3 +527,94 @@ asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
525 return ret; 527 return ret;
526} 528}
527#endif 529#endif
530
531
532#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
533
534/* Netlink family structure for quota */
535static struct genl_family quota_genl_family = {
536 .id = GENL_ID_GENERATE,
537 .hdrsize = 0,
538 .name = "VFS_DQUOT",
539 .version = 1,
540 .maxattr = QUOTA_NL_A_MAX,
541};
542
543/**
544 * quota_send_warning - Send warning to userspace about exceeded quota
545 * @type: The quota type: USRQQUOTA, GRPQUOTA,...
546 * @id: The user or group id of the quota that was exceeded
547 * @dev: The device on which the fs is mounted (sb->s_dev)
548 * @warntype: The type of the warning: QUOTA_NL_...
549 *
550 * This can be used by filesystems (including those which don't use
551 * dquot) to send a message to userspace relating to quota limits.
552 *
553 */
554
555void quota_send_warning(short type, unsigned int id, dev_t dev,
556 const char warntype)
557{
558 static atomic_t seq;
559 struct sk_buff *skb;
560 void *msg_head;
561 int ret;
562 int msg_size = 4 * nla_total_size(sizeof(u32)) +
563 2 * nla_total_size(sizeof(u64));
564
565 /* We have to allocate using GFP_NOFS as we are called from a
566 * filesystem performing write and thus further recursion into
567 * the fs to free some data could cause deadlocks. */
568 skb = genlmsg_new(msg_size, GFP_NOFS);
569 if (!skb) {
570 printk(KERN_ERR
571 "VFS: Not enough memory to send quota warning.\n");
572 return;
573 }
574 msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
575 &quota_genl_family, 0, QUOTA_NL_C_WARNING);
576 if (!msg_head) {
577 printk(KERN_ERR
578 "VFS: Cannot store netlink header in quota warning.\n");
579 goto err_out;
580 }
581 ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
582 if (ret)
583 goto attr_err_out;
584 ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
585 if (ret)
586 goto attr_err_out;
587 ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
588 if (ret)
589 goto attr_err_out;
590 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
591 if (ret)
592 goto attr_err_out;
593 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
594 if (ret)
595 goto attr_err_out;
596 ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
597 if (ret)
598 goto attr_err_out;
599 genlmsg_end(skb, msg_head);
600
601 genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
602 return;
603attr_err_out:
604 printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
605err_out:
606 kfree_skb(skb);
607}
608EXPORT_SYMBOL(quota_send_warning);
609
610static int __init quota_init(void)
611{
612 if (genl_register_family(&quota_genl_family) != 0)
613 printk(KERN_ERR
614 "VFS: Failed to create quota netlink interface.\n");
615 return 0;
616};
617
618module_init(quota_init);
619#endif
620